Workshops

Multiscale Processes in Fusion Plasmas

Overview

To achieve fusion in a magnetically confined plasma, it is necessary to hold a plasma of tens of meters cubed in a stable configuration for many seconds. Inside this plasma are physical processes on a vast range of space and time scales. Theoretical analysis of these problems has mainly focused on a single relevant space and time scale for each physical processes. For example, in the last decade the fusion community has made remarkable progress on calculating the small scale anisotropic kinetic turbulence that leads to the loss of heat from magnetically confined plasmas. It has become clear, however, that this single scale approach is inappropriate for key phenomena and that the interaction of disparate scales is nontrivial. A similar situation has arisen in inertial confinement fusion and in the relativistic interaction of beams and lasers with plasmas. In these high energy density (HED) plasmas the time scales range from the femtosecond laser period to the nanosecond plasma evolution time. While the fusion and high energy density communities have begun to develop multiple scale approaches, much needs to be done before predictive modeling of these plasmas is achieved. Clearly, the plasma community is not alone in facing such issues. Indeed, many areas have been addressing multiple scale issues for decades. The applied mathematics community has developed both specific and general techniques for the analysis of multiple scale problems. The plasma community has had limited exposure to these advances. Similarly, the applied mathematics community is largely unaware of the specific technical challenges in plasmas. This workshop aims to foster a dialogue between the fusion and applied mathematics communities.